In the use of CNC machines for machining various workpieces, it often has been the common practice for machine operators to determine the extent of usage and corresponding replacement of a cutting tool. Often, however, such judgment proves to be faulty, resulting in the use of worn tools, defective parts and the scrapping of such parts. In an effort to avoid such circumstances, certain machine control systems have been devised in a manner whereby an estimated time of usage of a tool is entered into such system, the times of usage of the tool is entered into such systems and subtracted from such estimated time and the expiration of the estimated time of usage is signaled to the operator indicating the necessity for replacement of the tool.
While such practice has been an improvement over prior practice, it has several serious shortcomings. The operator must know or be able to estimate a reasonable tool life in such an approach to have any value but seldom is sufficiently skilled, knowledgeable or experienced to make a suitable estimate. If originally estimated tool life values are found to be in appropriate as found in actual use, the operator is required to determine and enter a revised tool life value. When working with a wide variety to tools, such an adjustment is likely to be not only similarly imprecise in value but time consuming in accomplishing, negatively affecting productivity.
In view of the foregoing, it is this principal object to of the present invention to provide a system for determining and indicating the useful life of a tool of a CNC machine, diminishing the use of worn tools, the attendant production of misconfigured workpieces and improving productivity.